This application requests funds to continue biomedical and ecoengineering research directed toward a better understanding of potential health hazards arising from contamination of groundwater and soils with chemicals commonly found at hazardous waste sites. The pollutants under investigation include volatile organic solvents such as benzene and trichloroethylene and environmentally persistent compounds such as PCBs and PAHs. A group of 23 scientists from Michigan State University, the University of Michigan and Purdue University will engage in a collaborative and integrated research program involving 16 research projects. Research on remediation of contaminated sites includes basic studies of biodegradation processes and the use of chemically modified clays to adsorb and catalyze the destruction of pollutants. The transport of volatile organic compounds in the subsurface is studied experimentally and refined mathematical models describing this movement are being developed for use in predicting environmental concentrations before and after clean-up. Biomedical scientists are examining the mechanisms of toxicity of the same selected group of chemicals. Included will be studies of chemical-induced toxicity involving neutrophils, the reproductive system, and inhibition of intercellular communication and other fundamental cellular regulation processes. In addition, various biological systems are employed to determine the potential toxicity of products produced during ecoengineering studies of bacterial and chemical degradation. A novel system to assess the biological activity of mixtures of PCBs and PAHs will be developed using genetic engineering techniques. The study will produce several new, sensitive bioassay/biomarker systems for detection and monitoring of halogenated aromatic hydrocarbons. The research effort is accompanied by a training component which provides toxicology education to graduate students and postdoctoral fellows involved in site remediation research.